86 PROCEEDINGS OF THE l^ATIONAL, MUSEUM vol.88 



ventral sucker, length, 0.57 mm., breadth, 0.57 mm.; length of pre- 

 pharynx, 0.45 mm., of esophagus, 0.51 mm. ; ova, 0.054 by 0.030 mm. 



From bluefish : DlstOTnum, sp., Bull. U. S. Fish Comm. for 1899, p. 

 451, figs. 341-344, 1901. 



From dollarfish : Small, spinose distomes from the dollarfish, agree- 

 ing in most particulars with this species are here recorded. See also 

 Bull. U. S. Fish Comm. for 1899, pp. 454, 455, fig. 353, 1901. One, col- 

 lected August 13, 1904; length, life, 1.28 mm., breadth, 0.28 mm.; pre- 

 pharynx and esophagus but little longer than pharynx; concentric 

 bodies in excretory vessels, 0.02 mm. in diameter. One, collected 

 July 2, 1907. Measurements in balsam: Length, 0.96 mm.; breadth, 

 0.31 mm.; diameter of oral sucker, 0.06 mm., of pharynx, 0.04 mm., of 

 ventral sucker, 0.06 mm. ; ova, 0.054 by 0.027 mm. Concentric bodies 

 in excretory vessels of living worm ; prepharynx and esophagus short. 



An immature distome, found in a mass of appendicularia in the 

 stomach of this dollarfish, probably belongs here. It was minutely 

 spinose and very changeable in shape. Measurements, life: Length, 

 0.18 mm. ; maximum breadth at about the posterior third, 0.18 mm. ; 

 diameter of oral sucker, 0.04 mm., of ventral sucker, 0.03 mm., of con- 

 centric bodies in excretory vessels, 0.01 mm. 



Forty-two, collected August 30, 1917, from a 72-mm. dollarfish. 

 Two in life measured, the one 0.7 mm. in length and 0.45 mm. in 

 breadth, the other 0.35 mm. in length and 0.18 mm. in breadth. Meas- 

 urements in balsam: Length, 0.60 mm., breadth, 0.21 mm.; diameter 

 of oral sucker, 0.05 mm., of ventral sucker, 0.05 mm.; pharynx, length, 

 0.04 mm., breadth, 0.03 mm. ; ova, 0.051 by 0.033 mm. 



Five, collected July 8, 1918, from an 85-mm. dollarfish. 



One, collected July 25, 1918, from a 12-mm. dollarfish. The pre- 

 pharynx and esophagus are short; in other respects it is in close 

 agreement with distomes from the rudderfish. 



Two, collected August 21, 1918, from a 12-mm. dollarfish. The pre- 

 pharynx and esophagus are short ; in other respects it is in close agree- 

 ment with distomes from the rudderfish. 



Two, collected August 21, 1918, from a 125-mm. dollarfish. On ac- 

 count of the retraction of the oral sucker no prepharynx could be seen, 

 but there was a distinct esophagus. A second seminal vesicle could 

 be made out. 



From bonito: One (U.S.N.M. No. 8270), collected August 11, 1906. 

 Measurements in balsam : Length, 1.22 mm. ; breadth, 0.44 mm. ; oral 

 sucker, length, 0.75 mm., breadth, 0.57 mm. ; pharynx, length, 0.05 mm., 

 breadth, 0.06 mm. ; diameter of ventral sucker, 0.75 mm. ; ova, 0.056 by 

 0.027 mm. Prepharynx short, esophagus about as long as pharynx. 

 The vitellaria extend in front of the ventral sucker. This distome is 

 in close agreement with those from the rudderfish. 



